Evaluation of Long-term Protective Efficacy of Infant Hepatitis B Plasma-derived Vaccine Immunization

Objective To evaluate the long - term efficacy of newborns hepatitis B vaccine immunization.Methods By using birth-cohort combined with cross- sectional study to evaluate the three newborn cohorts of 1987- 1989 among those who had received hepatitis B vaccination.RIA and SPRIA were used to detect their HBV infectious signals and the re- sults were compared with the historical data.Results (1)After being immunized for 7,14,18 years the protective rates of 1987 - 1989 cohorts were 89.7%,94.8% and 8?.8% respectively,and there was no significant difference.The average positive rates of HBV protective antibody were 57.37 %,32.80 %,and 36.67 % respectively.The protective antibody of 14 and 18 years remained at the same level.(2)The average positive rate of HBV surface antigent was 1.99% 0 HBV protective antibody was 36.67%,and the total HBV surface antibody positive rate was 62.91%.Conclusions The universal new- born HB vaccination program has been proved to be effectively in controlling HBV infection.The protective efficacy of immu- nized people is stable.It is unnecessarily to carry out further HB reinforce immunization.